"The simplest high pass filter is a capacitor in resistor in series, where the voltage across the capacitor is used as output." Quote wikipedia The picture of this simple high pass filter is found at: http://upload.wikimedia.org/wikipedia/commons/f/fe/High_pass_filter.svg. I wonna get some things clear, because the circuit is drawn in a way that I am not used to. Which of the terminals are connected to the -pole of the voltage generator? And more importantly, can someone give me an intuitive understanding of why low frequencies are not allowed to pass through. What property of the capacitor makes the current get damped for low frequencies? If you switch the position of capacitor and resistor you get a low-pass filter. I don't see why switching these two would alter anything except the fact that you are now measuring the voltage across the capacitor. Isn't this the same as just switching the position of the voltmeter. Please take time to put some detail into your answers, since I am very confused about electronic components in general.